Control structure



Feb. 16, `1943. B, E SHAW 2,311,478

CONTROL STRUCTURE Filed April 14, 194i 2 sheets-Sheet 1 rllll Feb. 16', 1943. B, E SHAW 2,311,478

CONTROL STRUCTURE Filed April 14, 1941 2 Sheets-Sheet 2 INVENTOR. 3

Patented Feb. 16, v1943 CONTROL STRUCTURE Burton E. Shaw, Bristol, Ind., assignor to Penn Electric Switch Co., Goshen, Ind., a corporation of Iowa Application April 14, 1941, Serial: No. 388,563

(Cl. i4-100i) 9 Claims.

My present invention relates to a control structure wherein adjustable springs such as range and differential springs are provided with novel Calibrating mechanism.

One object of the invention is to provide calibrating means of simple and inexpensive construction for a control device mounted with or without other structures such as a relay in a casing, the various adjusting screws of the control device having elongated Shanks extending to a point exterior of one wall of the casing where each may be adjusted as desired.

Another object is to provide gear and pinion arrangements for driving calibrated scales so that the adjusting screws may be rotated through a plurality of revolutions and their proportional adjustments indicated by the calibrations so as to change the various settings of the control device as required for diierent types of installations.

A further object is to provide means for flush mounting the various Calibrating mechanisms under a cover plate on a wall of the casing for a control device with the cover plate serving to keep various studs, pinions and gears, etc., in their properly assembled positions when the cover plate is secured in position on the wall through which the adjusting screws extend.

Still a further object is to provide means for locking the various adjustments as desired against movement from their adjusted positions as a result of vibration or the like.

Still another object is to provide extension adjusting means for various parts of an electric circuit control ldevice with insulating sleeves surrounding the adjusting screws to prevent electrical contact of circuit wires therewith.

With these and other objects in view. my invention consists in the construction, arrangement and combination of the various parts of my device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, in which:

Figure 1 is a front elevation of a control structure embodying my invention with portions of the casing therefor shown in section.

Figure 2 is a plan view of my control structure.

Figure 3 is a sectional View on the line 3-3 of Figure 2 showing a switch of the control device closed as distinguished from its open position in Figure l.

Figure 4 is a plan view similar to Figure 2 with a cover plate of the device removed and the screws for holding it in position shown in section.

Figure 5 is a sectional view on the line 5 5 ci Figure 4.

Figure 6 is a plan view similar to Figure 2 showing a modified construction.

Figure 7 is a sectional view of Figure 6 on the line l-l thereof.

Figure 8 is a sectional view on the line 8-8 of Figure 6; and

Figure 9 is a front elevation similar to Figure l with parts broken away and other parts shown in section and illustrating the form of invention shown in Figures 6 and '7.

On the accompanying drawings I have used the reference character C to indicate generally a casing. The casing C has a bottom wall I0, side walls I2 and a top wall I3. Within the casing C a control device is provided, which in the present instance is shown as an automatic pressure operated switch structure. The control device includes a bell crank arm I4 pivoted at I5 and adapted to be operated in one direction by pressure within a bellows housing I6. A member ll serves as an operative connection between the bellows and the bell crank I4. Movement of the bellows is opposed by a range spring I6, the tension of which may be adjusted by an adjusting screw Ila.

The differential of operation of the control device is modied by a differential spring I8, which is adapted to be picked up by the arm Il as in Figures l and 5 t0 thereby increase the diierential of operation of the control device at one limit of its operation. At its other limit, spring I8 is ineifective due to its follower I9 resting against a stop plate 20 as in Figure 3. An adjusting screw 2| is provided for the spring I8 to thereby adjust the differential of operation of the control device.

The adjusting screws Ila and 2I extend through the wall I3 and are provided with slots 22 in their outer ends with which a screw driver may be associated for locating the adjusting screws. Each adjusting screw is provided with attened sides 23 with which pinions 24 slidably and non-rotatably coact. The pinions 24 are provided with discs 25 and mesh with gears 25. The gears 26 are rotatably mounted on shouldered studs 21 and on their faces are provided with calibrated scales showing various numerals or other indicia for reference purposes as illustrated in Figure 4. The indicia are visible through openings 28 in a cover plate 29.

The cover plate 29 serves to keep the pinions 24, discs 25 and gears 26 in their assembled positions and also to retain the shouldered studs 2'I tion to which they are adjusted. The cover plate` 29 has openings 33 to permit access to the lockingV screws 32.

The bell crank arm I4 is adapted to operate a switch arm 34 through the medium of a toggle spring 35. The toggle spring 35 is connected to a lever extension 35 of the switch arm 34 and the upper end of a toggle lever 31. The switch arm 34 and its extension 33 are pivoted on knife edge bearings at 38 with respect to a stationary bracket 39. The toggle lever 3'!v ispivoted on knife edge bearings 40 with respect to the upper end of the bell crank lever I4. The bell crank lever may swing. between switch opening and switch closing positions shown respectively in Figures l and 3 to effect operation of the switch arm 34 to its opposite positions.

The switch arm 34 carries movable contacts 40a which are engageable with stationary contacts 4I carried by an insulating block 42. A permanent horseshoe magnet 43 is carried by the block 42, the block in turn being mounted as by screws 44 on the bracket 39. A screw 45 is used to mount the magnet in position. The magnet is adapted to aiord snap action for the switch arm 34 by its cooperation with an armature 45 carried by the switch arm.

My invention may be applied to other control switch arrangements such as that shown in Figures 6, 7, 8 and 9 wherein a somewhat larger casing C is provided. The casing C has therein a panel 41 upon which a relay coil 48 is mounted. An armature 45 is provided for the relay and suitable wiring (not shown) for various installations may of course be used. It is desirable that the wires do not come in contact with the adjusting screws which in these gures are somewhat longer than in Figures 1 to 5. 'Ihey have accordingly been given reference numerals I'Ia and 2 Ia.. -Insulating sleeves 50 are provided surrounding the elongated adjusting screws I'Ia and 2Ia to prevent contact of wires with them.

Figures 6 to 9 also show an auxiliary control device including a bellows housing 5I which may be subjected to an emergency pressure such as the pressure from the high side of a refrigerant compressor. A spring 52 opposes the pressure acting on the bellows in the housing 5I so that whenever such pressure exceeds a predetermined degreeit will operate a bell crank 54 pivoted at 55 in a right-hand direction. A toggle spring 56 would then impart snap action to the bell crank 55 sothat an extension 54a thereof would swing the toggle lever 3l' toward the right in Figure 9 to open the switch contacts 40 and 4I to the position of Figure l in an obvious manner. .The bell crank 54 has a forked part coacting with a stop pin 54h extending from the wall of the casingC to limit the movement of the bell crank.

The setting of the spring 52 may be adjusted by-an adjusting screw 51 which, in a manner similar to the screws I'Ia and 2l extends through the upper wall I3ir of the casing C' and has the disc, locking screw, pinion, gear and stud arrangement already referred to by the reference numerals 25, 32, 24, 26 and 21. Thus my calibrating mechanism may be applied to any adjusting screw of the control device to accomplish the results contemplated in the objects above mentioned for my invention.

My calibration arrangement is such that the adjusting screws may be rotated through a plurality of revolutions without losing track of their position as the calibrationscri the gears 23 are arranged to take care of several revolutions of the adjusting screws. The gears 26 may be provided with means to stop them such as lugs or 1 portions 58 with teeth omitted to engage the pinion teeth and limit the rotation of the gears to slightly less than 360. The calibrations are readily observedthrough the sight openings 28 and after adjustments are made, the locking screws 32 can be used to retain the adjustments. As shown in Figure 7 one or more of the adjusting screws may be provided with a control knob 53 instead ofI merely a slot as at 22 requiring a tool such as a screw driver for rotating them.y

Some changes may be made in the construction and arrangement of the parts of my device without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims, any modified forms of structure or use of mechanical equivalents, which may be reasonably included within their scope.

I claim as my invention: s

l. In a control structure, a control device having range and diierential adjusting screws, a casing for said control device, said screws having shanks extending through a wall of said casing, a pinion on each of said shanks exterior of said wall, gears meshing with sai-d pinions, calibratedscales driven by said gears at reduced speed relative to the adjusting screws, a cover plate for said pinions, gears and scales, said cover plate being secured to said wall in sufficiently spaced relation thereto to permit operation of'said pinions and gears, studs for said gears and scales, said studs being mounted in said wall and retained in position by said cover plate, each of said pinions having a flange, locking screws having heads for engagin'g said flanges, said locking screws being l threaded into said wall and said cover plate being provided with openings lfor gaining access to said locking screws.

2. In a control structure, a control device having range and differential adjusting screws, a casing for said control device, said screws having shanks extending through a wall of said casing, a pinion on each of said Shanks exterior of said walls, gears meshing with said pinions, calibrated scales driven by said 'gears at reduced speed relative to said adjusting screws, a cover for said pinions, gears and scales, said cover being secured to said wall in suciently spaced relation thereto'.

to permit operation of said pinions and gears, and studs for said gears and scales, said studs being mounted in said wall and retained in position by said cover. f

3. In a control structure, a control device having range and differential adjusting screws, a casing for said control device, said screws having shanks extending through a wall of said casing, insulating sleeves on said Shanks, a pinion on each of said Shanks exterior of said walls, gears meshing with said pinions, calibrated scales driven by said gears, and a cover plate for said pinions;

gears and scales, said cover plate being securedv to said wall in sulicientlyspaced relation thereto to permit free operation of said pinions and gears.

4. A control structure comprising a control device having range and differential adjusting screws, said control device including a movable toggle member, an auxiliary pressure operating means for operating said toggle member, range and diierential adjusting screws fer said control device, a range adjusting screw for sai-d auxiliary pressure operating means, said adjusting screws having Shanks extending through a wall of said casing, a pinion on each of said shanks exterior of said wall, gears meshing with said pinions, calibrated scales, a cover for said pinions, gears and scales, said cover being secured to said wall in suiciently spaced relation thereto to permit operation of said pinions and gears, studs for said gears and scales, said studs being mounted in said wall, and retained in mounted position by said cover, each of said pinions having a flange, locking screws having heads for engaging said iianges, said locking screws being threaded into said wall, and said cover plate being provided with openings for gaining access to said locking screws.

5. A control structure comprising a control device having an adjusting screw, said adjusting screw having a shank extending through a wall of sai-d casing, an insulating sleeve on said shank, a pinion on said shank exterior of said wall, a gear meshing with said pinion, a calibrated scale driven by said gear at reduced speed relative to said adjusting screws, a cover for said pinion, gear and scale, said ccver being secured to said wall in spaced relation thereto, and a stud for said gear and scale, said stud being mounted in said wall and retained in position by said cover.

6. A control structure comprising a control device having range and differential adjusting screws, said control device including a movable toggle member, an auxiliary pressure operating means for operating said toggle member, range and differential adjusting screws for said control device, a range adjusting screw for said auxiliary pressure operating means, said adjusting screws having shanks extending through a wall of said casing, a pinion on each of said shanks exterior of said wall, gears meshing with said pinions, calibrated scales driven by said gears at reduced speed relative to said adjusting screws, a cover for said pinions, gears and scales, said cover bein'g secured to said wall in sufciently spaced relation thereto to permit operation of said pinions and gears, and studs for said gears and scales, said studs being mounted in said wall.

7. A control structure of the class described including a casing, a control device therein having pressure operated means, a spring opposing said means and a differential spring to be picked up by said means as it moves toward one of its limits of movement, an auxiliary pressure operated means for operating said control device and including a range adjusting spring, adjusting screws for each or" said springs, said screws having shanks extending through a wall of said casing, a pinicn cn each of said Shanks exterior oi said walls, gears meshing with said pinions, calibrated scales driven by said gears, a cover ior said pinions, gears and scales, said cover being secured to said wall, studs for said gears and scales, said studs being mounted in said wall, said pinions, gears, scales and studs being retained in assembled position by said cover plate, each of said pinions havingr a flange, and locking screws having heads ier engaging said flanges, said locking screws being threaded into said wall.

3. A control structure of the class described including a casing, a control device therein having pressure operated means, a spring opposing said means and a differential spring to be picked up by said means as it moves toward one of its limits of movement, adjusting screws for said range spring and said differential spring, an auxiliary pressure operated means for operating said control device and including a range adjusting spring, an adjusting screw for said last spring, said screws having Shanks extending through a wall of said casing, a pinion on each of said Shanks exterior of said wall, gears meshing with said pinions, calibrated scales driven by said gears at reduced speed relative to said adjusting screws, a cover for said pinions, gears and scales, said cover being secured to said wall in sufficiently spaced relation thereto to permit operation of said pinions and gears, and studs for said gears and scales and mounted in said wall.

9. In a control structure of the class described, a casing, a control device therein having pressure operated means, a spring opposing said means and a direrential spring to be picked up by said means as it moves toward one of its limits of movement, adjusting screws for said range spring and said diierential spring, an auxiliary pressure operated means for operating said control device and including a range adjusting spring, an adjusting screw for said last spring, said screws having shanks extending through a wall of said casing, a pinion on each of said Shanks exterior of said wall, gears meshing with said pinions, calibrated scales driven by said gears at reduced speed relative to said adjusting screws, a cover for said pinions, gears and scales, and locking screws threaded into said wall and cooperating with said pinions to lock said adjusting screws against rotation.

BURTON E. SHAW. 

